Dithiocarbamates and derivatives thereof



' T is the sulfolanyl group Patented June 2, 1953 UNITED STATES PATENT OFFICE DITHIOCARBAMATES AND DERIVATIVE S THEREOF Lyndon B. Tewksbury, Jr., Potsdam, N. Y., and Sylvia St Heikkila, Naugatuck, Conn., assignors to United States Rubber Company, New York, N. Y., a corporation of New Jersey No Drawing. Application April 18, 1947,

Serial No. 742,448

1 Claim. (01. 260-3321) 1 2 This invention relates to dithiocarbamates and 5-24 hours at a mildly elevated temperature such derivatives containing the essential N-substituted as 50-80 C. Butadiene sulfone thiocarbamyl sulfide group CH-CH R\ %S 5 (so: OHrCH R is prepared from reacting sulfur dioxide with butadiene-1,3.

In the case of sodium alkyl sulfolanyl-S dithiocarbamate, the formula would be where R is a functionally aliphatic group, and R is a thiolane nucleus. In particular, it relates 1 to the metal salts of a thiocarbamic acid having the formula i R s N--C-S-Na \N(IS-H r H a 2 R and R1 being as defined. H2 1 An object of the invention is to provid a new series of chemicals. A further object is to provide chemicals which may be used in the manufacture Examples of functionally aliphatic substituents of rubber goods derived from natural or synthetic epresented by a methyl ethy?) n'propyl rubber, which includes the polybutadienes, polylsopmpyl' lsobutyl' lsoamyl substituted butadienes, and modified polybutaclohexyli beltzyli anyl' methanyl n'octyL dienes, such as GRS and GRA. Another object 5 decyl: substltuted'alkyls' for example beta" is to provide chemicals which may be used as 2 methoxy ethyl betachlqroethyl' rubber vulcanization accelerators, or as lubricant of the Various l thlo' oil additives, or as intermediates in the preparalanes whlch may be reacted Wlth carbon dlsulfide tion of other chemicals. Other objects will be and base a apparent from the hereinafter description. 1,1-dioxo 3-methy1amino thiolane The chemicals may be prepared from a second- 1,1-di0x0 3-ethy1amino thiolane ary amine having the formula 1,1-dioxo 3-n-propylamino thiolane H 3-cyclohexylamino 1,1-dioxothio1ane A N- T 3-benzylamino 1,1-dioxo thiolane 3-allylamino 1,1-dioxo thiolane 1,1-dioxo 3-methallylamino thiolane 1,1-di0xo 3-isopropylamino thiolane H 1,1-dioxo 3-dodecy1amino thiolane n 1,1-dioxo 3-,8-methoxyethylamino thiolane.

In addition to the sodium salts, the corresponding salts of the following are also within the scope of the invention: potassium, ammooi nium (hypothetical metal) and substituted amby reacting the amine with carbon disulfide and momum' coppel? magnes.mm cadm.1um an alkali, whereby to form the water-soluble 4 mercury Fhrommm manganese lrgm alkali-metal dithiocarbamates. Other metal cobalt mckeliselfzmum and The salts such as those of calcium barium, iron, lead, Soluble i partlculaljly t Zmc and lead Salts etc., may be derived from the alkali-metal diare effecplvt? as vulcamzatlon accelerators thiocarbamates, e. g., from sodium dithiocar- The dlthmmbamste salts may be converjted bamate, by replacing the alkali-metal by reaction 5 to .esters by lzeactmg w broadly Varlous with a solution of the metal which is desired to hahdes such replace the sodium. 4-nitrochloro benzene The secondary amine may be prepared from ZA-dinitrochloro benzene butadiene sulfone and the appropriate aliphatic Triphenyl methyl chloride primary amine by heating the two together, e. '55 Benzal chlorid where A is a functionally aliphatic radical, and

The dithiocarbamates may also be reacted with so-called positive chlorine compounds such as:

Monochloramine (NHz- C1) N-chlorcyclohexylamine N-chlorpiperidine N-chlor acetamide N-chlor succinamide N-chlor di n-butylamine N-chlor diethylamine N-chlor morpholine N-chlor isopropylamine N-chlor diamylamine to form sulfenamide type compounds by a procedure as illustrated in Examples 7, 9, 11, and 15 below. Example? below describes the preparation of S (N-ethyl N-sulfolanyl-3 thiocarbamyl) sulfenamide, having the formula In the name, S indicates that the thiocarbamyl group is joined to the sulfur of the sulfenamide (SNI-Iz) nucleus. To differentiate between the nitrogens, the thiocarbamyl nitrogen is labeled N as indicated.

The sulfen-amides may conform to either the depending on the type of positive chlorine compound used. For example, where N-chlorcyclohexylamine is reacted with an alkali-metal salt, the reaction is. illustrated as follows:

Where N-chlor diethylamine is used, the corresponding end product is of the type R S ethyl Nt 1 s N/ ethyl Where N-chlor acetamide is used, the end product is of the type Where N-chlor morpholine is used, the end product is of the type NttS n CH2CH2 Of particular value, are the thiuram disulfides formed by oxidation of the dithiocarbamate with iodine, chlorine, sodium hypochlorite, acidified hydrogen peroxide, etc. Exemplary of useful thiuram disulfides are:

Bis (methyl sulfolanyl-B) thiuram disulfide Bis (ethyl sulfolanyl-B) thiuram disulfide Bis (n-propyl sulfolanyl-B) thiuram disulfide Bis (n-butyl sulfolanyl-3) thiuram disulfide Bis (n-amyl sulfolanyl-3) thiuram disulfide Bis (n-octyl sulfolanyl-3) thiuram disulfide Bis (n-dodecyl sulfolanyl-3) thiuram disulfide Bis (isopropyl sulfolanyl-3) thiuram disulfide Bis (isobutyl sulfolanyl-3) thiuram disulfide Bis (isoamyl sulfolanyl-S) thiuram disulfide The following examples are given to illustrate the preparation of the chemicals, the parts being by weight:

Example 1(a).1,1-diomo-3-n-butylamino thiolane 1,1-dioxothiolane-3 (butadiene sulfone) 59 g., 146 g. n-butylamine and 146 cc. water are heated at 65-70 C. for 13% hours in a flask equipped with a reflux condenser. The unreacted amine and most of the water are removed in a good vacuum from a water bath at approximately 40-50 C. The oily residue weighs 97.3 g. The theoretical yield of 1,1-dioxo-3-n-butylamino thiolane is 95.5 g., indicating the presence of a small amount of water.

Example 1(b).-Sodium n-butyl suZjoZanyl-S- dithiocarbamate A mixture of 47.7 g. 1,1-dioxo 3-n-butylamino thiolane and 10.0 g. sodium hydroxide in 250 cc. water is treated in an ice bath with stirring with 16.2 g. carbon disulfide. After 3 hours stirring, an orange solution of sodium n-butyl sulfolanyl-B dithiocarbamate is obtained. By evaporation under reduced pressure, a heavy oil is obtained, which solidified on trituration with acetone. The white crystalline solid softens at -100 C. and decomposes at 128 C.

Example 2.--Potassium n-butyl sulfolanyZ-3-di- 'thiocarbamctte A mixture of 47.7 g. S-n-butylamino 1,1-dioxothiolane and 16.5 g. potassium hydroxide in 250 cc. water is stirred 4 hours at 10-15 C. with 16.2 g. carbon disulfide and the mixture filtered. The clear filtrate is an aqueous solution of the potassium salt of n-butyl sulfolanyl-3 dithiocarbamic acid. By evaporation under reduced pressure and trituration with alcohol, a crystalline material softening at 71-76 C. and decomposing at 87 C. is obtained.

Example 3.-Barz'um n-butyl sulfoZanyZ-3 d1- thiocarbamate An aqueous solution of sodium n-butyl sulfolany1-3 dithiocarbamate is mixed with an aqueous solution of barium chloride instoichiometric amounts. The barium dithiocarbamate precipitates. After Washing and drying it melts at 165-170 C. with decomposition.

Example 4.Ferroas n-batyl salfolanyl-S dithiocarbamate This salt is prepared from ferrous sulfate and sodium n-butyl sulfolanyl-3 dithiocarbamate in Water solution. Precipitation occurs immediately. The dark brown salt after drying melts with decomposition beginning around 140 C.

Example 5(a) .1,1-dtoxo-3-ethylamino thiolane Butadiene sulfone (A g.) and 90 cc. of a 70% aqueous solution of ethylamine are heated 5% hours at 6570 C. in a thick walled flask. The unreacted ethylamine and water are removed in a vacuum from a Water bath at approximately -50 C. An oil amounting to g. and consisting of 1,1-dioxo-3-ethylamino thiolane is ob- .tained.

Example 5 (b) .--Soclium ethyl sulfolanyl-3 dithiocarbamate Two tenths mol of the above amine is mixed with 33.3 cc. (0.2 mol) of 6 N sodiumhydroxide and 70 cc. water, and the mixture is cooled to 10 C. while 9.0 cc. carbon disulfide are added slowly with stirring.

After 2 hours, a clear orange brown solution of the sodium ethyl sulfolanyl-3 dithiocarbamate is obtained.

Example 6.Zinc ethyl sulfolanyl-3 dithiocarbamate On treatment of a water solution of sodium ethyl sulfo1anyl-3 dithiocarbamate with an equivalent amount of zinc sulfate, a yellow precipitate immediately forms which is filtered, washed, and

dried.

Example 7 .S (N -ethyl N -sulfolanyl-3 thiocarbamyl) sulfe'namide A water solution containing 0.2 mol of the sodium salt of the dithiocarbamate of Example 5 is treated at 05 C. With a slight excess of monochloramine solution. The product after filtration and washing with water is recrystallized from alcohol. An 80% yield of S-(N-ethy1-l I'- sulfolanyl-B thiocarbamyl) sulfenamide melting 103-5" C. is obtained.

Analysis Theory Found 11. O 10. 64 i3if:::::i::jii:::ii:i 37.8 37.58

Example 8(a) .-1,1-clioxo 3-allylamino thiolane Butadiene sulfone (59 g.), allylamine (114 g.) and 114 cc. water are heated in a thick-walled flask 10 hours at 70 C. The unreacted amine and Water are removed under vacuum from a water bath at 40-50" C. The oily residue consisting of 1,1-dioxo 3-allylamino thiolane amounts to 73.4 g.

Example 8(b) .-Sodium allyl sulfolanyl-B' dithiocarbamate Thirty-five grams of 3-allylamino 1,1-d ox0 thiolane are treated in the cold with 8 g. sodium hydroxide in 200 cc. water and 7.6 g. carbon d1- sulfide. After 1 /2 hours stirring, an orange solution of sodium allyl su1folanyl-3 dithiocarbamate is obtained.

Example 9.'-S (N -allyl-N-sulfolany'l-3' thiocarbamyl) salfenamzde The dithiocarbamate solution of Example 8 is treated with excess monochloramine as previously described. S-(N'-allyl-N' sulfolanyl 3 thiocarbamyl) sulfenamide is obtained as a white powder of melting range -86 C.

Example 10.-Zinc allyl suzfbzanyz-a dithiocarbamate The dithiocarbamate solution of Example 8 is mixed with an equivalent amount of zinc sulfate. There immediately precipitates the corresponding insoluble zinc dithiocarbamate. 1

Example 1 1 .S-' (N -butyl-N -salfolanyl-3- thiocarbamyl) salfenamide This material having a-melting range of 72-76 C. is prepared from monochloramine and sodium butyl sulfo1anyl-3-dithiocarbamate of Example 1.

Example 12.--S0diam methyl salfolanyl-3 dithiocarbamate Thirty grams 1,1-dioxo 3-methyl amino thiolane are converted to the dithiocarbamate with 8 g. sodium hydroxide and 10.8 cc. carbon disulfide in 200 cc. water at 10-15" C.

Example 13.--Bis (methyl sulfolanyl-3) thiuram disulfide The dithiocarbamate solution of Example 12 is diluted to 500 cc. and cooled to 0-5 C. At this temperature it is treated with asolution of 11 g. 30% hydrogen peroxideand 9.8 g. sulfuric acid in 35 cc. Water. The product which precipitates during the peroxide addition is filtered, washed with water and dried. After digestion with alcohol, 31.8 g. bis (N-methyl-N-sulfolanyl- 3) thiuram disulfide melting 172-175 C. with decomposition are obtained.

Example 14.-B2's (ethyl salfolanyl-) thiuram disulfide The aqueous solution of sodium ethyl sulfolanyl-3 dithiocarbamate (0.2 mol) (Example 5) is diluted to three times its volume (approximately 300 cc.) cooled to below 5 C., and treated with 0.1 mol iodine as an aqueous potassium iodide complex solution. After standing overnight, the white product is filtered, washed with water, and dried. A yield amounting to- 73% of his (ethyl sulfolanyl-B) thiuram disulfide as a white powder melting 162-16 9 C. is obtained.

Example 15.S-(N-methyl-N-sulfolanyl-3 thiocarbamyl) sulfenamide A dithiocarbamate solution prepared according to Example 12 is treated with monochloramine. The product after filtration and washing with Water melts hi l- C.

Example 16.Zinc n-batyl sulfolanyl-B dithiocarbamate This zinc salt is obtained as a white powder by treating the sodium salt of the dithiocarbamate (Example 1) with the calculated amount of zinc sulfate.

Example 17.--Ethyl sulfolanylammonium salt of ethyl salfoZanyl-3 aithz'oecarbamic acid To a cold solution of (34.2 g.) 1,1-dioxo 3-ethylamino thiolane in 75 cc. ether, a solution of 6.02 cc. carbon disulfide in 15 cc. of ether is added. After stirring for several hours a viscous oil consisting of ethyl su1folany1-3 ammonium ethyl su1fo1any1-3 dithiocarbamate separates.

7 The following examples are given to illustrate the efiectiveness of the chemicals as rubber vulcanization accelerators, the parts being by weight:

Example 18 The various chemicals of this invention are Chemical I-S-(N-ethyl-N'-su1folany1-3 thiocarbamyl) sulfenamide Chemical IIBis (ethyl 'su1fo1anyl-3) thiuram disulfide Chemical IIIS-'(N'-methyl 1N sulfolanyl-3 thiocarbamyl.) sulfenamide Chemical IV-Zinc n-butyl su'lfolanyl-3 dithiocarbamate Stock Above Master Batch Chemical :1 Chemical II Chemical III Chemical IV...-

The various stocks are cured 30, 45, 60, and 90 minutes "at 45 pounds per square inch steam pressure.

Cumin Elongaiv Tensile Strength (p. s.-1.-) Minutes at tion,

45 Percent Stock A Stock B Stock 0 Stock D 300 10 950 310 030 500 1, 0 1,710 690 1,420 1 Break 2,120-660 2,350-040 1,1085-686 aosasss "s00 830 1,050 810 780 500 1 1,790 2,150 1,740 1, 780 Break 2,600-655 2,320-520 2,11a59s 2,010-503 300 950 1,115 900 900 500 1,010 2,:250 2, 010 1,040 Break; 2,-400-540 2, 550-526 2, 520-500 2, 570- 300 990 1, 200 1110 I 1, 015 500 2,200 2,400. 1900 1.11..." Break. assasss 2,-650-520, 2,-280-576 2,0154% The new accelerators are equally efiective in natural rubber tread compounds, and in latex;

"compounds or other conventional vulcanizable compounds of natural or synthetic rubbers. The various vulcanizable synthetic rubbers are herein considered equivalent to rubber, examples being the Buna types (polymers essentially derived from butadiene-1,3) such as Buna N (rubbery copolymer of butadiene-1,3 and acrylonitrile) and Buna S (rubbery copolymer of butadiene-1,3 and styrene). In place of sulfur, other conventional vulcanizing agents susceptible to acceleration may be included.

The accelerators may, if desired, be employed with conventional accelerator activators used with other known accelerators. Also, the new accelerators may be used in combination with known accelerators such as diphenyl guanidine, or conventional thiazyl sulfide accelerators, such as mercaptobenzothiazole and dibenzothiazyl sulfide, etc.

The proportion of the accelerators is the same as the proportion used with other conventional accelerators in the vulcanization of the various elastomers.

Other ratios of compounding ingredients other than those given in Example 18, as well as other desired fillers, pigments, softeners, antioxidants, and the like may be employed in the production of various types of rubber compounds, as will be apparent to those skilled in the art of vulcanization of rubber.

Having thus described our invention, what we claim and desire to protect by Letters Patent is:

A sulfenamide of the formula where R is an unsubstituted sulfolanyl-B group.

LYNDON B. TEWKSBURY, JR. SYLVIA .S. HEIKKILA.

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